David Lilienfeld was in the water with his brother and two friends at Gordon’s Bay to the southeast of the city when the shark struck at around 12.30pm.

Witnesses described how the five-metre creature dragged him underwater as his brother looked on helplessly. He and their friends managed to pull him onto nearby rocks, but he had died by the time paramedics were able to reach him by boat.

Mr Lilienfeld, from nearby Camps Bay, had represented South Africa at the World Bodyboarding Championship in the Canary Islands in November. Pat Harris, the South African Bodyboarding Association vice chairperson, said he was both accomplished and popular. “It’s a humongous loss," he added.

Controversy now surrounds the filming of a documentary entitled Shark Men in the bay, in which researchers had been using bait to lure sharks close to their boat. Shark experts had warned that the practice could cause a shark attack – the documentary team’s permit to film has now been cancelled.

Craig Lambinon, a spokesman for the National Sea Rescue Institute, said the shark that attacked Mr Lilienfeld was unusually large and as many as six others had been spotted in the sea shortly afterwards.

“The shark that attacked was four or five metres in length, really a massive shark, and is believed to have been a Great White,” he said.

“It amputated the man’s right leg at the hip – there were no other injuries.

”The deceased man's father arrived on scene and police trauma counsellors are assisting the family."

He said that the beach was a popular body boarding and surfing spot, and there had been no other shark attacks there for many years.

“Following the incident, there were a number of other sharks shopped in the area – up to six in total. That is very unusual so there is obviously going to be controversy about the documentary that was being filmed there.”

Andre Visser, from ambulance service ER24, said paramedics who arrived on the scene saw Mr Lilienfeld’s leg floating in the water with the surfboard cord still attached, but were unable to recover it.

The last fatal shark attack in the False Bay area which covers Gordon’s Bay was in January 2010 and saw Zimbabwean Lloyd Skinner killed as he swam in Fish Hoek.

Last September, Michael Cohen, 47, a British man, lost his right leg after going swimming at the same beach despite warnings from shark spotters that a Great White was in the area.